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2017-09-29 Science & Technology
U.S. Military's Most Powerful Cannon - Electromagnetic Railgun - Shoots 100 miles - Mach 7
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Posted by Besoeker 2017-09-29 07:52|| || Front Page|| [3 views ]  Top

#1 'Murica!!
Posted by DarthVader 2017-09-29 08:12||   2017-09-29 08:12|| Front Page Top

#2 How much do you lead a satellite?
Posted by Skidmark 2017-09-29 10:35||   2017-09-29 10:35|| Front Page Top

#3 Satellite travels roughly 8 km/second.

Projectile travels at 2.4 km/sec

Let's say Satellite at roughly 400 km altitude, so 167 seconds in projectile travel at which point the sat has moved 1,336 km in an orbital arc. Ran out of time to do the geometry.
Posted by Mullah Richard 2017-09-29 12:37||   2017-09-29 12:37|| Front Page Top

#4 OK I'm sold. When does the sidearm version come to Brownells?
Posted by Large Peacock6383 2017-09-29 12:37||   2017-09-29 12:37|| Front Page Top

#5 The 100 mile capability is overkill. A dash mounted fire control system would be ideal however.
Posted by Besoeker 2017-09-29 12:42||   2017-09-29 12:42|| Front Page Top

#6 The 100 mile capability is overkill.

???

Sounds about right to me.
Posted by gorb 2017-09-29 14:14||   2017-09-29 14:14|| Front Page Top

#7 42,543 km circumference of Satellite's arc (assuming circular and not elliptical). Satellite travels 3% of circumference in 167 seconds.

Your lead angle should be about 11.3 degrees in the direction of travel, if I've done this right (lot's more assumptions). Seems like a lot, but that little sucker travels a bit in the just under three minutes it would take for 'contact' by the slug.

Geostationary sats sit out at ~36,000 km, so that's a straight shot, only it would take the projectile almost two hours to get there.

Lot's of assumptions (like the rail gun having no distance limitations or the projectile never slowing down), but we're talking spherical chickens in a vacuum.

Big Friggin' Lasers would work better for small space targets.

Besoeker, I do like the thought of dash-mounted controls, especially when I have to drive in metro Chicago, Minneapolis or Milwaukee. Would want to have to have front and rear delivery systems, though.

And a bigger alternator.
Posted by Mullah Richard 2017-09-29 16:24||   2017-09-29 16:24|| Front Page Top

#8 Where does the energy come from to power this beast? The US had another "breakthrough" technology: pneumatic cannons firing dynamite shells in the USS Vesuvius(1888). Interesting idea, air is an ever present propellant, right? Only thing is that explosives are a much more efficient way of storing energy...
Wake me up when they solve the powerplant and energy storage issues...
Posted by magpie 2017-09-29 18:19||   2017-09-29 18:19|| Front Page Top

#9 I understand the chemistry/physics of propellants limits how fast a shell can be propelled. The limit for a railgun is much higher.

There are some youtube videos of people who have built their own railguns.
Posted by phil_b 2017-09-29 19:37||   2017-09-29 19:37|| Front Page Top

#10 That video was too short, I was almost finished.
Posted by bbrewer126 2017-09-29 20:58||   2017-09-29 20:58|| Front Page Top

#11 Great work, MR!
Posted by Skidmark 2017-09-29 21:21||   2017-09-29 21:21|| Front Page Top

23:20 Slonter Bourbon7177
23:12 trailing wife
22:44 trailing wife
22:08 Skidmark
22:04 Skidmark
21:43 Alaska Paul
21:28 Frank G
21:21 Skidmark
21:13 Frank G
21:12 3dc
20:58 bbrewer126
20:24 3dc
19:37 phil_b
19:28 charger
19:22 newc
19:19 Skidmark
19:00 Skidmark
18:48 Skidmark
18:22 magpie
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17:29 g(r)omgoru
17:27 Shipman
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